diff options
Diffstat (limited to 'drivers/iio/light/acpi-als.c')
| -rw-r--r-- | drivers/iio/light/acpi-als.c | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/drivers/iio/light/acpi-als.c b/drivers/iio/light/acpi-als.c new file mode 100644 index 000000000..c35e2f8df --- /dev/null +++ b/drivers/iio/light/acpi-als.c @@ -0,0 +1,232 @@ +/* + * ACPI Ambient Light Sensor Driver + * + * Based on ALS driver: + * Copyright (C) 2009 Zhang Rui <rui.zhang@intel.com> + * + * Rework for IIO subsystem: + * Copyright (C) 2012-2013 Martin Liska <marxin.liska@gmail.com> + * + * Final cleanup and debugging: + * Copyright (C) 2013-2014 Marek Vasut <marex@denx.de> + * Copyright (C) 2015 Gabriele Mazzotta <gabriele.mzt@gmail.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include <linux/module.h> +#include <linux/acpi.h> +#include <linux/err.h> +#include <linux/mutex.h> + +#include <linux/iio/iio.h> +#include <linux/iio/buffer.h> +#include <linux/iio/kfifo_buf.h> + +#define ACPI_ALS_CLASS "als" +#define ACPI_ALS_DEVICE_NAME "acpi-als" +#define ACPI_ALS_NOTIFY_ILLUMINANCE 0x80 + +ACPI_MODULE_NAME("acpi-als"); + +/* + * So far, there's only one channel in here, but the specification for + * ACPI0008 says there can be more to what the block can report. Like + * chromaticity and such. We are ready for incoming additions! + */ +static const struct iio_chan_spec acpi_als_channels[] = { + { + .type = IIO_LIGHT, + .scan_type = { + .sign = 's', + .realbits = 32, + .storagebits = 32, + }, + /* _RAW is here for backward ABI compatibility */ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_PROCESSED), + }, +}; + +/* + * The event buffer contains timestamp and all the data from + * the ACPI0008 block. There are multiple, but so far we only + * support _ALI (illuminance). Once someone adds new channels + * to acpi_als_channels[], the evt_buffer below will grow + * automatically. + */ +#define ACPI_ALS_EVT_NR_SOURCES ARRAY_SIZE(acpi_als_channels) +#define ACPI_ALS_EVT_BUFFER_SIZE \ + (sizeof(s64) + (ACPI_ALS_EVT_NR_SOURCES * sizeof(s32))) + +struct acpi_als { + struct acpi_device *device; + struct mutex lock; + + s32 evt_buffer[ACPI_ALS_EVT_BUFFER_SIZE]; +}; + +/* + * All types of properties the ACPI0008 block can report. The ALI, ALC, ALT + * and ALP can all be handled by acpi_als_read_value() below, while the ALR is + * special. + * + * The _ALR property returns tables that can be used to fine-tune the values + * reported by the other props based on the particular hardware type and it's + * location (it contains tables for "rainy", "bright inhouse lighting" etc.). + * + * So far, we support only ALI (illuminance). + */ +#define ACPI_ALS_ILLUMINANCE "_ALI" +#define ACPI_ALS_CHROMATICITY "_ALC" +#define ACPI_ALS_COLOR_TEMP "_ALT" +#define ACPI_ALS_POLLING "_ALP" +#define ACPI_ALS_TABLES "_ALR" + +static int acpi_als_read_value(struct acpi_als *als, char *prop, s32 *val) +{ + unsigned long long temp_val; + acpi_status status; + + status = acpi_evaluate_integer(als->device->handle, prop, NULL, + &temp_val); + + if (ACPI_FAILURE(status)) { + ACPI_EXCEPTION((AE_INFO, status, "Error reading ALS %s", prop)); + return -EIO; + } + + *val = temp_val; + + return 0; +} + +static void acpi_als_notify(struct acpi_device *device, u32 event) +{ + struct iio_dev *indio_dev = acpi_driver_data(device); + struct acpi_als *als = iio_priv(indio_dev); + s32 *buffer = als->evt_buffer; + s64 time_ns = iio_get_time_ns(indio_dev); + s32 val; + int ret; + + mutex_lock(&als->lock); + + memset(buffer, 0, ACPI_ALS_EVT_BUFFER_SIZE); + + switch (event) { + case ACPI_ALS_NOTIFY_ILLUMINANCE: + ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &val); + if (ret < 0) + goto out; + *buffer++ = val; + break; + default: + /* Unhandled event */ + dev_dbg(&device->dev, "Unhandled ACPI ALS event (%08x)!\n", + event); + goto out; + } + + iio_push_to_buffers_with_timestamp(indio_dev, als->evt_buffer, time_ns); + +out: + mutex_unlock(&als->lock); +} + +static int acpi_als_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) +{ + struct acpi_als *als = iio_priv(indio_dev); + s32 temp_val; + int ret; + + if ((mask != IIO_CHAN_INFO_PROCESSED) && (mask != IIO_CHAN_INFO_RAW)) + return -EINVAL; + + /* we support only illumination (_ALI) so far. */ + if (chan->type != IIO_LIGHT) + return -EINVAL; + + ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &temp_val); + if (ret < 0) + return ret; + + *val = temp_val; + + return IIO_VAL_INT; +} + +static const struct iio_info acpi_als_info = { + .read_raw = acpi_als_read_raw, +}; + +static int acpi_als_add(struct acpi_device *device) +{ + struct acpi_als *als; + struct iio_dev *indio_dev; + struct iio_buffer *buffer; + + indio_dev = devm_iio_device_alloc(&device->dev, sizeof(*als)); + if (!indio_dev) + return -ENOMEM; + + als = iio_priv(indio_dev); + + device->driver_data = indio_dev; + als->device = device; + mutex_init(&als->lock); + + indio_dev->name = ACPI_ALS_DEVICE_NAME; + indio_dev->dev.parent = &device->dev; + indio_dev->info = &acpi_als_info; + indio_dev->modes = INDIO_BUFFER_SOFTWARE; + indio_dev->channels = acpi_als_channels; + indio_dev->num_channels = ARRAY_SIZE(acpi_als_channels); + + buffer = devm_iio_kfifo_allocate(&device->dev); + if (!buffer) + return -ENOMEM; + + iio_device_attach_buffer(indio_dev, buffer); + + return devm_iio_device_register(&device->dev, indio_dev); +} + +static const struct acpi_device_id acpi_als_device_ids[] = { + {"ACPI0008", 0}, + {}, +}; + +MODULE_DEVICE_TABLE(acpi, acpi_als_device_ids); + +static struct acpi_driver acpi_als_driver = { + .name = "acpi_als", + .class = ACPI_ALS_CLASS, + .ids = acpi_als_device_ids, + .ops = { + .add = acpi_als_add, + .notify = acpi_als_notify, + }, +}; + +module_acpi_driver(acpi_als_driver); + +MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>"); +MODULE_AUTHOR("Martin Liska <marxin.liska@gmail.com>"); +MODULE_AUTHOR("Marek Vasut <marex@denx.de>"); +MODULE_DESCRIPTION("ACPI Ambient Light Sensor Driver"); +MODULE_LICENSE("GPL"); |